Cross-cultural adaptation to Brazilian Portuguese of the indication for common toxicity criteria grading of peripheral neuropathy questionnaire

Abstract

Background: Multiple myeloma (MM) is a common hematological malignancy, and chemotherapy-induced peripheral neuropathy (CIPN) is one of its most significant adverse drug reactions. While CIPN can be managed through dose adjustments or treatment discontinuation, its assessment relies on patient-reported symptoms. The need for validated tools to accurately assess CIPN and support clinical decisions is critical to improving patient outcomes and ensuring more effective management strategies. Aim: To perform the cross-cultural adaptation of the Indication for Common Toxicity Criteria Grading of Peripheral Neuropathy Questionnaire (ICPNQ) to Brazilian Portuguese. Method: The cross-cultural adaptation process was conducted in five stages: (a) translation, (b) synthesis of translations, (c) submission of the translated version to a panel of experts, (d) pre-testing with the target population, and (e) backtranslation into the original language. Results: The translation team included a specialist in onco-hematology, and the adapted version of the ICPNQ was evaluated by 20 healthcare professionals (nurses, pharmacists, and physicians) with an average of 9.5 years of experience in onco-hematology. The Content Validity Index (CVI) of the overall instrument was 0.98, while the CVIs for presentation and clarity were 0.98, and 0.97 for applicability. A pilot test was performed with 22 patients with MM in a specialized outpatient clinic for onco-hematological diseases in a university hospital. The patients were predominantly male (54.55%), over 65 years (59.09%), and using at least one neurotoxic drug (81.82%). Back-translation confirmed the semantic and cultural equivalence of the instrument’s items. Conclusion: The Brazilian Portuguese version of the ICPNQ demonstrates semantic, idiomatic, cultural, and conceptual equivalence, suitable for application in the Brazilian context.